The Aptian Crato Konservat-Lagerstätte is renowned for its exceptionally preserved fossils in lacustrine laminated limestones. Although previous works on this site include numerous taxonomic studies, its taphonomy remains a subject of debate. Herein, we present new data on the taphonomy of decapod crustaceans preserved in wrinkle laminites, highlighting the role of microbial mats in enhancing fossil preservation. Our results suggest that benthic microorganisms may have promoted protection and organic mineralization of some of the allochthonous to parautochthonous organic remains within the microbial laminites of the Crato lake. Overall, this work provides the first empirical evidence that the preservational pathways of the fossils in the Crato Konservat-Lagerstätte involved microbial mats.

Tide-influenced deposits of the Pennsylvanian Rock Lake Shale Member, Stanton Formation, Missouri and Kansas (U.S.A.), contain well-preserved evidence of the burrowing activities of protobranch bivalves, including locomotion (Protovirgularia) and locomotion-resting (Protovirgularia-Lockeia) trace fossils. Protovirgularia shows three distinct morphotypes, the morphological variability of which was controlled by external factors such as substrate conditions, toponomy, and undertrack deficiency. Extreme morphological modifications of Protovirgularia and/or Lockeia, represented by irregular bilobate structures, probably result from erosion and subsequent partial passive filling of the original biogenic structures. In addition, very well-preserved trace fossils showing intergradation of a fan-shaped cluster of ridges with Protovirgularia-Lockeia structures are interpreted as a compound biogenic structure that represents locomotion, resting, and feeding activities of burrowing protobranch bivalves.